C# ASP.NET MVC Calculating sales tax

Question

I am trying to calculate sales tax in a view page and cannot seem to get it to work.

The code below is working other than producing a Total with sales Tax. The Sales Tax is singular and is not on every record. I basically just need to apply Tax to the subtotal and show the Total.

What I have tried:

totalOrder += (item.Quantity * item.SellingPrice);

total = (totalOrder * 8%);

It does not like the 8%

Using a Variable

var tax = .08;
var tax = 8%

 ((totalOrder * tax) / 100);

All if the above gives errors - Cannot use * with decimal etc.

Below is the code for that section of the view. Thanks for your help

<tbody>
                            @foreach (var item in Model.InvoiceDetail)
                            {
                                <tr>
                                    <td>@Html.DisplayFor(modelItem => item.Quantity)</td>
                                    <td>@Html.DisplayFor(modelItem => item.Material)</td>
                                    <td>@Html.DisplayFor(modelItem => item.Description)</td>
                                    <td>$@Html.DisplayFor(modelItem => item.SellingPrice)</td>

                                    <td>@string.Format("{0:C2}", (item.Quantity * item.SellingPrice))</td>
                                </tr>
                                totalOrder += (item.Quantity * item.SellingPrice);

                                total = (totalOrder * 8%);
                            }
                        </tbody>
                    </table>
                    <h5 style="margin-left: 80%;"><b>Sub Total :</b> @string.Format("{0:C2}", totalOrder)</h5>
                    <h5 style="margin-left: 80%;"><b>Tax :</b> 8%</h5>
                    <h5 style="margin-left: 80%;"><b>Total Due :</b> @string.Format("{0:C2}", total)</h5>

I also am using this:

decimal totalOrder = 0;
decimal total = 0;

Screen Shot of amounts

[EDIT] Current code

decimal totalOrder = 100.1m;
decimal tax = .08m;
decimal total = totalOrder * (1.0m + tax);

<tbody>
                            @foreach (var item in Model.InvoiceDetail)
                            {
                                <tr>
                                    <td>@Html.DisplayFor(modelItem => item.Quantity)</td>
                                    <td>@Html.DisplayFor(modelItem => item.Material)</td>
                                    <td>@Html.DisplayFor(modelItem => item.Description)</td>
                                    <td>$@Html.DisplayFor(modelItem => item.SellingPrice)</td>

                                    <td>@string.Format("{0:C2}", (item.Quantity * item.SellingPrice))</td>
                                </tr>
                                //totalOrder += (item.Quantity * item.SellingPrice);


                            }
                        </tbody>
                    </table>
                    @{totalOrder += (Model.TotalCount * Model.PricePer);}
                    <h5 style="margin-left: 80%;"><b>Sub Total :</b> @string.Format("{0:C2}", totalOrder)</h5>
                    <h5 style="margin-left: 80%;"><b>Tax :</b> 8%</h5>
                    <h5 style="margin-left: 80%;"><b>Total Due :</b> @string.Format("{0:C2}", total)</h5>

Answer 1

Looks like you have two issues(and maybe one future issue), if I am interpreting your variable names correctly.

1. Your total variable is only getting set to the tax value, and not the totalOrder and the tax
2. var tax = 8% is not valid c#, you need to use a decimal like var tax = .08
3. Another thing to keep in mind, which I do not think you have gotten to yet, is rounding issues with sub cent numbers.

The code should be something like:

decimal totalOrder = 100.01m;
decimal tax = .08m;
decimal total = totalOrder * (1.0m + tax);

Answer 2

Thanks to Nathan Werry I managed to get this problem resolved. I will explain what I did after each snippet.

Here is the code that was created for the Sales Tax:

decimal totalOrder = 0m;
decimal tax = .08m;
@{decimal totalTax = totalOrder * (tax);
  decimal total = totalOrder + totalTax;}

TotalOrder just reflects that the Quantity * SellingPrice is calculated below and there is no need to add anything to it.

Tax is tax at .08m

TotalTax is the TotalOrder * Tax

And finally you have to add the tax to the TotalOrder.

Below is the finished code for the foreach statement:

<tbody>
                            @foreach (var item in Model.InvoiceDetail)
                            {
                                <tr>
                                    <td>@Html.DisplayFor(modelItem => item.Quantity)</td>
                                    <td>@Html.DisplayFor(modelItem => item.Material)</td>
                                    <td>@Html.DisplayFor(modelItem => item.Description)</td>
                                    <td>$@Html.DisplayFor(modelItem => item.SellingPrice)</td>

                                    <td>@string.Format("{0:C2}", (item.Quantity * item.SellingPrice))</td>
                                </tr>
                                totalOrder += (item.Quantity * item.SellingPrice);


                            }
                        </tbody>
                    </table>
                    @{decimal totalTax = totalOrder * (tax);
                        decimal total = totalOrder + totalTax;}
                    <h5 style="margin-left: 80%;"><b>Sub Total :</b> @string.Format("{0:C2}", totalOrder)</h5>
                    <h5 style="margin-left: 80%;"><b>Tax :</b> 8%</h5>
                    <h5 style="margin-left: 80%;"><b>Total Due :</b> @string.Format("{0:C2}", total)</h5>